Is Blender suitable, or perhaps overkill, for making 2d graphic of water flowing in pipe?
Yes it's possible to create a 2D graphic like this in Blender. Perhaps it's a bit much, but Blender is pretty easy to use for this kind of stuff. Here's an animation I whipped up in Blender of something like what I think you're describing:


Simply switch the render engine to cycles in a new scene, align the camera to front view (NUMPAD 1 and then ctrl-alt-NUMPAD 0) and add in shapes such as planes and make sure to use emission materials for everything. Use the displace modifier with a texture and keyframe the size values at frames 0 and 70 to be 0.25 and 0.7.